For machineries equipped with rotatable bearings immersed within lubrication oil, the oil needs to be regularly replenished (e.g. through regular gravitational feeding) at an optimal-drops/minute from a relatively lofty reservoir of oil. In the latter regard, a relatively lofty outlet-line conveys the oil from the reservoir to an intake-line communicating with the machinery's rotatable bearings. The optimal-drops/minute is empirically calculated according to a given machine's optimal-requirement for oil per unit time.
In the prior art, the quest for gravitational feeding of oil at the optimal-drops/minute is pursued by utilizing a manually adjustable threaded needle-valve (e.g. 114) positioned along the tubular outlet-line, and this is reliable only so long as the oil viscosity remains substantially constant. Accordingly, such commonly utilized manually adjustable threaded needle-valves cannot be blindly relied upon if the oil viscosity changes, such as effected by: water condensation, sludge or other transient oil impurity, ambient temperature changes, etc.
A representative type such machinery having immersed bearings requiring regular oil replenishment by gravitational means and utilizing such prior art manually adjustable threaded needle-valves (e.g. 114), is the water pump machinery depicted in drawing FIG. 1. Machinery embodiment 100 is employed for pumping subterranean water "W" upwardly along a well-casing 200 surrounding vertical-axis 101A and upwardly terminating as a lateral-spout 201. Well-casing 200 surrounds tubular oil-casing 103 and which in turn surrounds drive-shaft 101 extending along vertical-axis 101A. Upwardly pumped water "W" occupies the annular space between well-casing 200 and oil-casing 103, and lubrication oil 104 occupies the annular space between oil-casing 103 and drive-shaft 101. Thus, the incrementally spaced bearings 102 of drive-shaft 101 and which bear against oil-casing 103, are immersed within lubrication oil 104. Pumping machinery 100 also comprises a hollow pedestal 105 resting upon the earth's surface "ES" and surrounding the upper terminii of oil-casing 103 and drive-shaft 101. Motive power to drive-shaft 101 is supplied via rotatable lateral-shaft 106 and gearing 107 located loftily above earth "E". Thus, as lateral-shaft 106 is powerably rotated (e.g. gasoline engine, etc.), drive-shaft 101 is also rotated and whereby its subterranean helices (not shown) cause subterranean water "W" to be pump upwardly between well-casing 200 and oil-casing 103.
For pumping apparatus 100, lubrication oil 104 is constantly replenished from a reservoir 110 of oil mounted (e.g. 109) to pedestal part 108. This reserved oil gravitationally flows through an outlet-line 111 ultimately communicating (113) with the annular space between drive-shaft 101 and oil-casing 103. At the outlet-line portion 112, the prior art utilizes a threaded needle-valve (e.g. 114) that is empirically manually established at a threaded setting which hopefully will replenish oil 104 at the optimum-drops/minute. But, as previously mentioned, such needle-valve threaded setting cannot be indefinitely relied upon if the oil (104) viscosity changes.